The police are now scouting Facebook pictures for evidence of underage drinking, so before you post that fun night out, you might want to think twice. Several students at the University of Wisconsin-La Crosse faced underage drinking fines after pictures of him at a party surfaced on his Facebook page.

Of age hosts of parties can face legal action too: Theodore and Laura Berent hosted a party where they served alcohol to minors and found themselves in trouble with local law enforcement after pictures ended up on Facebook. And, if your employer finds your drinking questionable, you can be fired. A Barrow County, Ga. teacher was fired because she posted pictures of her drinking at the Guinness Factory and in Temple Bar in Dublin. Although she claims she didn’t appear intoxicated in the pictures, she couldn’t erase the fact that she used an explicative word on her Facebook, which also led to her removal.

3. Post Evidence That You Cheated On Your Significant Other

Divorce lawyers know how to use Facebook too. According to a survey by the American Academy of Matrimonial Lawyers, 81 percent of its members have used or faced evidence taken from Facebook, MySpace, Twitter and other social networking sites. Facebook is the number one go to place to find dirt on your client’s spouse. Sixty-six percent of the time proof of an affair from a social networking site comes from Facebook.

4. Update Your Status While Robbing A House

If you’re going to do something illegal, it’s pretty obvious that you shouldn’t leave evidence – which also includes logging out of your Facebook profile if you so happened to check in while robbing a house. Had this thief not stopped to check his profile on his way out, he may have never been caught. Instead, now there’s irrefutable evidence he was in the victim’s home illegally.

5. Ask For Help So You Can Plagiarize

Asking people for what the homework assignment was on Facebook is fine, but when you start copying answers from posts on walls and groups it becomes plagiarism. Universities in the UK are on to this trick, especially since a Cambridge University survey revealed that one in two students had cheated. Forty nine percent of the 1,000 people questioned said they had copied someone else’s work, with 82 percent admitting that they copied straight from Wikipedia.

However, Facebook saved the day on this one: A friend watched the video from her home surveillance security system and recognized one of robbers as one of the Virginia woman’s 500 “friends.”

9. Brag About All Your New, Expensive Items

Yeah, we know you want to tell all your friends about that cool new computer, iPad and iPod you got for your birthday, but remember there may be some disingenous people reading your Facebook update as well. British-based Legal & General warns that Facebook users might be making themselves potential targets when posting about their expensive new items, and when coupled with letting people know you are out of the home for a while on vacation or at a special event, it can be an invitation to be robbed. Similarly, posting personal details like your address and phone number can make it even easier for those robbers to determine where you live and when you aren’t home.